Mainstream of scientific community recognize the global warming. It is indeed happening. By the beginning of the 20th century, the average surface temperature of the earth has increased 1.1 F (0.6 C). In the last 40 years, the air temperature has increased 0.5 F (0.2- 0.3 C). Global warming has been going on in the last 400- 600 years, but the fastest in the 20th century.

As a result, the natural environment has been changing. We can see glaciers are fading away gradually. In the last 40 years, the thickness of north polar glaciers has dropped 40% of the original. The global sea level is arising. More and more researches show that plants and animals respond to the climate change by changing their behavior patterns.

Do you find that you have more allergies in recent years? In spring, you sneeze and the eyes itch more frequently? Researches show that the increase of carbon dioxide and the rise of air temperature bring forward the flowering period of plants and thus produce more pollen.

Animals have migrated to higher ground. In the 20th century, people find that they only can see lovely chipmunks and squirrels when they climb higher. Global warming had forced various animals to migrate higher.

Lakes “leak”. In the last decades, there are 125 lakes in North Pole gone. Global warming results in the melting of permafrost at the bottom of lakes and thus, the water penetrates into the soil.

Satellites revolve faster and faster. Influences of global warming achieve to the outer space. Though the earth’s outermost layer of air is thin, it still produce resistance to satellites. Thus, engineers need to adjust the orbit of satellites.

More and more forest fires happen. Global warming increases the dryness of forests and thus, raises the risks of fires.

When atmospheric layer has been damaged; the environment has been polluted and the globe has been warming, many influences are brought to human beings and the earth, both positive and negative. For example, as temperature rises, subpolar areas may be more suitable for human beings to live in. The rise of carbon dioxide promotes the photosynthesis and thus, plants grow faster. The above two examples show the positive influences. However, negative influences are more profound. For example, it influences human beings’ health. Extreme high temperature will cause many health problems, such as malaria, cholera, kala-azar and so on. As climate changes, some tropical diseases can spread to extratropic region.